1. Field of the Invention
This invention relates to a printing press, and in particular to a press for intaglio printing, including printing of etchings and engravings.
2. Description Relative to the Prior Art
The art of intaglio printing dates back at least to the 15th century, where it was practiced by such well known artists as Rembrandt and Durer. It has developed over time and continues as a method of graphic artistic expression to the present.
The forms of intaglio printing are characterized by having the art work incised on a flat plate (i.e., a printing block plate); either into a ground layer covering the plate or into the surface of the plate itself. The plate surface used, and the means of forming the lines of the print determine the actual classification of the work. However, all intaglio processes involve filling the incised lines of the plate's finished drawing with ink, and carefully removing all remnants of ink from the flat, uncut surfaces of the plate. The plate is then covered with an appropriately wetted print paper (i.e., print fabricating material) which is in turn covered with resilient layers of material such as felt, and then run through a press which applies pressure to the felt and paper forcing it down into the inscribed lines of the plate so that ink is picked up and transferred to the paper.
Because paper fibers must be forced down into the lines and grooves of the inked plate to effect the ink transfer, large forces, uniform across the width of the plate, must be applied to the felt/paper layers as they traverse the press. Presses of the prior art utilize a fixed structure on which is mounted a massive movable bed onto which the plate is laid for printing. The bed is generally propelled by a lower driven roller which causes the plate to move on auxiliary rollers along the length of the table carrying the plate beneath the fixed print roller. The print roller, supported on end bearings fixed in heavy brackets secured to the table, is pressed down onto the felt/paper layers with pressure sufficient to effect the ink/paper transfer as the bed is rolled along the table in a plane parallel to, and at a fixed distance from, the print roller axis, by an appropriate motive means. In the prior art, the print rollers have been substantial steel cylinders with diameters of from 4" and up, and the lower rollers consisting of steel cylinders with diameters of from 3" and up. These heavy rollers are used to provide uniform pressure and to maintain straightness and parallelism over their full widths of the bed from 12" to several feet, and require heavy, rigid support structures. The bed itself must be weighty to resist flexing under the printing forces. Thus the intaglio press of the prior art is a heavy and unwieldy structure. The present invention provides performance equivalent to that obtainable by the presses of the prior art, but with a substantial reduction in complexity and weight.